马拉松属于超长距离比赛,优秀运动员跑完全程要两个多小时,在这样长时间的运动中,运动员所消耗的体内能源物质很多。在运动过程中,主要供给能量的物质是肌肉里贮藏的肌糖元。当肌肉中肌糖元被消耗掉一部分以后,肝脏中贮存的肝糖元立即分解成葡萄糖进入血液,经血液运输到肌肉,再转变为肌糖 Marathon belongs to the ultra-long distance competition, excellent athletes run the whole process to more than two hours, during such a long period of exercise, athletes consume a lot of energy substances in the body. During exercise, the main source of energy is muscle glycogen stores. When muscle muscle glycogen is consumed part of the liver glycogen stored immediately after decomposition of glucose into the blood, transported to the muscle by the blood, and then converted to muscle sugar